いくつかの非常に優れたライブラリを使用したソリューションはたくさんありますが、同じ問題を小さなスタンドアロン コード スニペットで処理する必要がありました。これは、他のすべての場合と同様に、中心ではなく上/左を原点として使用する行列変換の ie6、ie7、および ie8 問題も解決します。
//
// Rotate a <DIV> element
//
// - DIV position must be absolute or relative
// - Will use the center point of DIV as origin for tilt
//
// I think it will work on most browsers (including ie6, ie7 & ie8)
//
function divRotate( divObj, divTop, divLeft, divHeight, divWidth, newAngleDeg )
{
var radAngle = Math.PI * newAngleDeg / 180;
var spinAngle = radAngle;
if ( window.navigator.userAgent.indexOf ( 'MSIE ' ) <= 0 || typeof document.documentElement.style.opacity!='undefined' )
radAngle = -radAngle;
var sinAngle = parseFloat(parseFloat(Math.sin(radAngle)).toFixed(8));
var cosAngle = parseFloat(parseFloat(Math.cos(radAngle)).toFixed(8));
var m11 = cosAngle;
var m12 = -sinAngle;
var m21 = sinAngle;
var m22 = cosAngle;
if ( window.navigator.userAgent.indexOf ( 'MSIE ' ) <= 0 || typeof document.documentElement.style.opacity!='undefined' )
{
divObj.style.WebkitTransform = 'matrix('+ m11 +','+ m12 +','+ m21 +','+ m22 +',' + 0 + ',' + 0 + ')';
divObj.style.MozTransform = 'matrix('+ m11 +','+ m12 +','+ m21 +','+ m22 +',' + 0 + 'px,' + 0 + 'px)';
divObj.style.msTransform = 'matrix('+ m11 +','+ m12 +','+ m21 +','+ m22 +',' + 0 + ',' + 0 + ')';
divObj.style.OTransform = 'matrix('+ m11 +','+ m12 +','+ m21 +','+ m22 +',' + 0 + ',' + 0 + ')';
divObj.style.transform = 'matrix('+ m11 +','+ m12 +','+ m21 +','+ m22 +',' + 0 + ',' + 0 + ')';
divObj.style.top = divTop + 'px';
divObj.style.left = divLeft + 'px';
return;
}
var sinSpinAngle = -parseFloat(parseFloat(Math.sin(-spinAngle)).toFixed(8));
var cosSpinAngle = parseFloat(parseFloat(Math.cos(-spinAngle)).toFixed(8));
var sinAnglePerp = parseFloat(parseFloat(Math.sin(radAngle-Math.PI)).toFixed(8));
var cosAnglePerp = parseFloat(parseFloat(Math.cos(radAngle-Math.PI)).toFixed(8));
var halfHeight = divHeight/2;
var halfWidth = divWidth/2;
var radius = Math.sqrt(halfHeight*halfHeight + halfWidth*halfWidth);
var ulx = divLeft + halfWidth - radius*cosSpinAngle + sinAnglePerp*halfHeight;
var uly = divTop + halfHeight - radius*sinSpinAngle + cosAnglePerp*halfHeight;
var urx = radius*cosSpinAngle + divLeft + halfWidth + sinAnglePerp*halfHeight;
var ury = radius*sinSpinAngle + divTop + halfHeight + cosAnglePerp*halfHeight;
var lrx = radius*cosSpinAngle + divLeft + halfWidth - sinAnglePerp*halfHeight;
var lry = radius*sinSpinAngle + divTop + halfHeight - cosAnglePerp*halfHeight;
var llx = divLeft + halfWidth - radius*cosSpinAngle - sinAnglePerp*halfHeight;
var lly = divTop + halfHeight - radius*sinSpinAngle - cosAnglePerp*halfHeight;
divObj.style.filter = "filter: progid:DXImageTransform.Microsoft.Matrix( M11="+m11+", M12="+m12+", M21="+m21+", M22="+m22+", sizingMethod='auto expand' );";
var spinTop = Math.min( uly, ury, lry, lly );
var spinRight = Math.max( ulx, urx, lrx, llx );
var spinBottom = Math.max( uly, ury, lry, lly );
var spinLeft = Math.min( ulx, urx, lrx, llx );
divObj.style.top = spinTop + 'px';
divObj.style.right = spinRight + 'px';
divObj.style.bottom = spinBottom + 'px';
divObj.style.left = spinLeft + 'px';
}